amishjha@gmail.com, When you start the upgrade tool does it give you a message that your player is in recovery mode?
If so you need to install a full version firmware befor you can load your dump.bin. If you have already loaded a full firmware and your dump will not load did you run the repair.bat on the dump after you extracted it.
The "UNKNOWN FLASH ERROR" can also be a sign that the memory chip has a pin connection problem.
Try gently applying pressure to the chip while upgrading. You can do this by placing a few layers of thin card on top of the chip and replacing the cover. The card should be enough so that it makes contact with the players case and puts an even pressure on the chip.